Summary of work: The BLSA data set of 36 years of experience with the diagnostic tests for diabetes and with outcome variables known to be repeated to plasma glucose concentration (conversion to clinical diabetes, coronary heart disease incidence, mortality) is the most comprehensive experience in men and women across the adult age span. An analysis of these data was provided to the Expert Committee of the American Diabetes Association. These data were cited in the July 1997 publication of new criteria for the diagnosis of diabetes. These data were also provided to a WHO Committee which issued its report in August 1998. Neither set of standards made an adjustment for age. We have analyzed BLSA data and have collaborated with Dr. Barrett-Connor of the Rancho Bernardo Study and with Dr. Kathryn Flegal of the NHANES-III Study to examine the applicability of the new standards to older men and women. All three population studies show that there are serious problems in the balance of fasting glucose and glucose tolerance data that are of increasing seriousness with advancing age. The Diabetes Prevention Program has completed its recruitment phase. Approximately 10% of the randomized participants are age 65 or over, but 20% of the recruited participants are 60 yrs of age or older. The ADA revision of diagnostic standards caught the DPP in mid-stream since a fraction of those already recruited (those with fasting glucose values of 126 to 139 mg/dl) converted to instant diabetics at entry. Nevertheless overall recruitment goals were exceeded. Analysis of glycosylated hemoglobin and of microalbuminuria are continuing. These tests are performed on all participants on each visit. At this time the GRC Core Laboratory is not performing these analyses. Analysis of these variables in relation to such variables as the fasting glucose and two- hour post-glucose values will be conducted in the coming years. Comprehensive inventory of all banked samples is nearly complete. To date over 340,000 individual samples have been inventoried. - Fasting glucose, Glucose tolerance, Mortality, Coronary heart disease, Microalbuminuria, Glycated hemoglobin - Human Subjects